First I used a center punch to get a divot right in the middle of the bolt I broke. Then I used a small drill bit (around 1/8") to get a decent hole started in what was left of the bolt. I started the drill at a crazy angle to get the tip of the bit centered as much as I could on the bolt, then slowly moved the drill up while drilling to get as straight on axis with the bolt as I could.

When I had the drill on axis I started drilling down into the bolt. As I was drilling the bolt started spinning down, which meant it wasn't fully tight. At that point I took an old screwdriver, ground it narrower so the end was more like a pointed square, hammered it into the hole I drilled into the bolt, and turned it counter clockwise until it came out (just like an easy-out).

Honestly I got lucky. Had that bolt been tighter it would have been much more of a bitch. I've removed MANY stripped 1/4"x20 bolts from Harley engine items before and got it down to a science by now. My plan B was to drill and tap it for a helicoil. That fastener was one of the small bolts on the rocker plate for an Evo. The 5/16" bolts carry most of the load there.

 

sure, it happens way more than you think.
by their nature, they are brittle and add heat cycles, easy to fall. i remember changing heads on an old's diesel with new bolts and the last one snapped, bummer, had to remove head to get dutchman out. it is best to sneak up on torque values than set the wrench and go hog wild.
remember too, values change between new and old bolts. offshore ALL critical fasteners were changed out. every year, ball ring bolts were checked and torqued and after 5, changed out.

 

I had a similar situation with a passenger floorboard bolt ... Snapped off in the frame while riding down the road by myself ... Went back and got what was left, threw it in the Tour Pack ... For grins and giggles I wrote a letter to HD Customer service and they agreed that there was a "quality issue" with the bolt ( it used the single bolt mounting style ) ... They replaced the boards and mounts with the new updated two bolt style free of charge

 

Not denying the bolt weakend over time.. I'm pretty careful when it comes to torque values depending on bolt size. I changed out the rocker bolts twice now with in 17 years with grade 5 bolts. The following link is a bolt kit specific to the Rocker Assemblies..
https://www.denniskirk.com/gardner-w...AaAhtNEALw_wcB

 

I wouldn't say it was a problem of the 90s. I had the same thing happen on my 05 1200. Rocker box to head bolt. I got lucky too. It didn't snap off flush and left just enough sticking out of the hole to get a hold of and it wasn't tight either. It was easily removed.

 

I broke a rocker support bolt on my Evo, turned out that I had got the positions mixed up (one side of the head uses longer bolts).

I had mistakenly installed the longer bolt into the wrong side, the bolt broke before it reached the required torque.

The broken piece spun right out no problem. So I got another long bolt and did the same damned thing...

I finally got my head out of my a$$ and realized the mistake, but now I was short 2 bolts (PN 3500).

The dealer was no stock, I tried some hardware vendors but no luck. I finally called the local Fastenal store, and they did have the 5/16"-18x2-3/4" Gr8 bolt, but I had to buy a whole box of them.

So, if any of you guys need a 5/16"-18x2-3/4" grade 8 bolt...
I have 48 spares.....

 

It happens. A lot. Defects, stretches/damages from previous removal and installs, corrosion, etc.
I did it for a living, and run 3 shops now, and cannot count how many times I and my techs have had to dig out a grade 8 bolt (or any fastener) before it's time.

The art of extraction is what sets apart the good techs

 

I'll take that as a compliment.

 

Two years ago I bought some grade 8 bolts from an Ace Hardware store for work. Looked the same as in the pic. I snapped two of them off when tightening them. Everyone agreed they did not appear to be grade 8. I filed a complaint with Ace and with some quasi government agency in, if I remember correctly, in Virginia. Never heard anything back from anyone. I did find out that Bush Sr signed the Fastener Quality Act when he was in office in an attempt to stop the cheap Chinese stuff from killing us.

 

One of the problems with grade 8 bolts, is that they can be brittle. If the UTS (ultimate tensile strength) is not required, a lower grade will stretch well before breakage. and provide better service.
Off shore manufacturers must be avoided at all costs, as real material content can be questionable at best.